/*
silverPDF is sponsored by Aleyant Systems (http://www.aleyant.com)

silverPDF is based on PdfSharp (http://www.pdfsharp.net) and iTextSharp (http://itextsharp.sourceforge.net)

Developers: Ai_boy (aka Oleksii Okhrymenko)

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above information and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR SPONSORS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

*/
#region PDFsharp - A .NET library for processing PDF
//
// Authors:
//   Stefan Lange (mailto:Stefan.Lange@pdfsharp.com)
//
// Copyright (c) 2005-2008 empira Software GmbH, Cologne (Germany)
//
// http://www.pdfsharp.com
// http://sourceforge.net/projects/pdfsharp
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.
#endregion

using System;
using System.Diagnostics;
using System.Collections;
using System.Text;
using System.IO;
using PdfSharp.Pdf.Advanced;
using PdfSharp.Pdf.IO;

namespace PdfSharp.Pdf.Annotations
{
  /// <summary>
  /// Represents the annotations array of a page.
  /// </summary>
  public sealed class PdfAnnotations : PdfArray
  {
    internal PdfAnnotations(PdfDocument document)
      : base(document)
    {
    }

    internal PdfAnnotations(PdfArray array)
      : base(array)
    {
    }

    /// <summary>
    /// Adds the specified annotation.
    /// </summary>
    /// <param name="annotation">The annotation.</param>
    public void Add(PdfAnnotation annotation)
    {
      annotation.Document = this.Owner;
      this.Owner.irefTable.Add(annotation);
      Elements.Add(annotation.Reference);
    }

    /// <summary>
    /// Removes an annotation from the document.
    /// </summary>
    public void Remove(PdfAnnotation annotation)
    {
      if (annotation.Owner != Owner)
        throw new InvalidOperationException("The annotation does not belong to this document.");

      Owner.Internals.RemoveObject(annotation);
      Elements.Remove(annotation.Reference);
    }

    /// <summary>
    /// Removes all the annotations from the current page.
    /// </summary>
    public void Clear()
    {
      for (int idx = Count - 1; idx >= 0; idx--)
        Page.Annotations.Remove(page.Annotations[idx]);
    }

    //public void Insert(int index, PdfAnnotation annotation)
    //{
    //  annotation.Document = this.Document;
    //  this.annotations.Insert(index, annotation);
    //}

    /// <summary>
    /// Gets the number of annoations in this collection.
    /// </summary>
    public int Count
    {
      get { return Elements.Count; }
    }

    /// <summary>
    /// Gets the <see cref="PdfSharp.Pdf.Annotations.PdfAnnotation"/> at the specified index.
    /// </summary>
    public PdfAnnotation this[int index]
    {
      get
      {
        PdfReference iref = null;
        PdfDictionary dict = null;
        PdfItem item = Elements[index];
        if ((iref = item as PdfReference) != null)
        {
          Debug.Assert(iref.Value is PdfDictionary, "Reference to dictionary expected.");
          dict = (PdfDictionary)iref.Value;
        }
        else
        {
          Debug.Assert(item is PdfDictionary, "Dictionary expected.");
          dict = (PdfDictionary)item;
        }
        PdfAnnotation annotation = dict as PdfAnnotation;
        if (annotation == null)
        {
          annotation = new PdfGenericAnnotation(dict);
          if (iref == null)
            Elements[index] = annotation;
        }
        return annotation;
      }
    }

    //public PdfAnnotation this[int index]
    //{
    //  get 
    //  {
    //      //DMH 6/7/06
    //      //Broke this out to simplfy debugging
    //      //Use a generic annotation to access the Meta data
    //      //Assign this as the parent of the annotation
    //      PdfReference r = Elements[index] as PdfReference;
    //      PdfDictionary d = r.Value as PdfDictionary;
    //      PdfGenericAnnotation a = new PdfGenericAnnotation(d);
    //      a.Collection = this;
    //      return a;
    //  }
    //}

    /// <summary>
    /// Gets the page the annotations belongs to.
    /// </summary>
    internal PdfPage Page
    {
      get { return this.page; }
      set { this.page = value; }
    }
    PdfPage page;

    /// <summary>
    /// Fixes the /P element in imported annotation.
    /// </summary>
    internal static void FixImportedAnnotation(PdfPage page)
    {
      PdfArray annots = page.Elements.GetArray(PdfPage.Keys.Annots);
      if (annots != null)
      {
        int count = annots.Elements.Count;
        for (int idx=0;idx<count;idx++)
        {
          PdfDictionary annot = annots.Elements.GetDictionary(idx);
          if (annot != null && annot.Elements.Contains("/P"))
            annot.Elements["/P"] = page.Reference;
        }
      }
    }

    /// <summary>
    /// Returns an enumerator that iterates through a collection.
    /// </summary>
    public override IEnumerator GetEnumerator()
    {
      return new AnnotationsIterator(this);
    }

    class AnnotationsIterator : IEnumerator
    {
      PdfAnnotations annotations;
      int index;

      public AnnotationsIterator(PdfAnnotations annotations)
      {
        this.annotations = annotations;
        this.index = -1;
      }

      public object Current
      {
        get { return this.annotations[this.index]; }
      }

      public bool MoveNext()
      {
        return ++this.index < this.annotations.Count;
      }

      public void Reset()
      {
        this.index = -1;
      }
    }
  }
}
